1. Field of the Invention
The present invention relates to an image processing apparatus.
2. Description of Related Art
A prior art image processing apparatus such as a printer capable of automatically turning off a power source is commonly known in the art. For example, when a printing request is not provided from a host device for a predetermined time period, such an image processing apparatus of prior art automatically turns off the power source thereof.
Japanese Un-examined Patent Application Publication No. H8-25757 discloses a prior art printer capable of automatically turning off a power source. Specifically, the prior art printer turns off the power source thereof when response requests are transmitted to all host devices connected through a network, and no reply is provided for a predetermined time period. Such a printer ensures an energy saving, for example, even when a user forgets to turn off the power source.
However, since the response requests are transmitted to all of the host devices through the networks, the replies corresponding to the response requests are transmitted from the host devices regardless of being in use in a case where respective host devices are being started. For example, when one of the host devices is not in use while being started, the prior art printer determines that the host device is being used based on the reply corresponding to the response request. In other word, the prior art printer cannot turn off the power source in such a situation. Consequently, the prior art printer has a problem that the energy is not saved in such a situation.